The L-class submarines were built to two distinctly different designs at four different shipyards. The two designs were from the Electric Boat Company (EB) of New York City (later Groton, CT.) and the Lake Torpedo Boat Company (LTB) of Bridgeport, CT. While very similar in military and operational capability, the two designs were vastly different in installed equipment, interior arrangement, and external appearance.
The L-1 through L-4, and L-9 through L-11 were of the EB design and were built at an EB subcontractor, the Fore River Shipbuilding Co. of Quincy, MA. L-5 through L-8 were of the LTB design, with L-5 built at the Lake yard in Bridgeport, CT., the L-6 and L-7 built at Craig Shipbuilding in Long Beach, CA., and the L-8 built under license at the Portsmouth Navy Yard in Kittery, ME.
The L-class made up the bulk of the submarines that the USN deployed to the European war zone during WWI. They operated out of the Azores and Bantry Bay, Ireland on anti U-boat patrols. While in the war zone off Ireland, the boats had the letter "A" painted on the fairwater directly adjacent to their name. This was intended to reduce confusion between the American boats and the Royal Navy's L-class submarines.
L-1 (Submarine No. 40, later SS-40)
L-1 riding at anchor while on sea trials, March or April 1916, probably off Provincetown, Mass. A low-lying shore line with houses can be seen in the background, reminiscent of Cape Cod. The L-class were the first US submarines designed to carry a deck gun of any sort, in this case a 3"/23 caliber Mk 9 gun. But it wasn't until the L-9 that guns were installed during construction. The L-1 through L-8 were retrofitted later with the gun. As you can see the L-1 has no gun in this early photo.
L-2 in an unknown location, approximately fall of 1916. In July of 1918 while patrolling in the Irish Sea, a large explosion rocked the L-2 about 25 feet on her beam. A torpedo aimed at her by a German U-boat had seemingly detonated prematurely. A periscope was sighted so the L-2 immediately submerged and made an unsuccessful attempt to ram the submarine. with her primitive sonar she couldn't track the U-boat well under water, plus the U-boat had superior under water speed. Later it was suspected that a U-boat had indeed attempted to fire upon the L-2, but another U-boat, the U-65, was unknowingly in the way and was hit by the torpedo meant for L-2. Some time later when the L-2 was dry docked her hull plating was noted to be heavily dented from the close by explosion. The U-65 never returned to her port.
L-3 with sailing yachts, early in her career, approximately 1916. The location is unknown, but could be Newport, R.I. Notice the complete lack of a bridge structure. It would be added later during the war.
L-4 underway off Berehaven, Ireland, summer of 1918. She sports the original version of the "chariot" style bridge, a necessity in the rough waters of the Irish Sea and the eastern Atlantic. It greatly helped to protect the bridge watchstanders from weather while on the surface. It would later become a larger and permanent metal structure.
This photo of L-5 was taken in the early fall of 1918, possibly in Bermuda. The boat is maneuvering alongside a pier, getting ready to tie up after a run at sea. Lines have been flaked out on deck and the two sailors on the bow seem to be ready to throw a "heevey", a small diameter line with a weight on the end. It is used to throw over to a pier or tender, so that the large, heavy mooring line can then be pulled over and secured. L-5 was a Lake design boat built at Lake's yard in Bridgeport, CT.
The Lake design L-6 is shown under construction by the Craig Shipbuilding Company, Long Beach, CA., June 30, 1917. Note the circular flood port openings for the watertight superstructure, the open oval shaped torpedo loading hatch, and the very incomplete state of the conning tower fairwater. Although not yet in commission, there is a sailor standing watch on the forward deck with a rifle.
L-7 with her crew on deck, alongside a submarine tender, most likely the USS Alert (Submarine Tender #4). The location is unknown, but is likely Mare Island Navy Yard. The date is approximately 1918-1919.
L-8 seen from the deck of the USS Charles Whittemore, fall 1918 in the eastern Atlantic during an anti U-boat patrol. The Whittemore was acting as a decoy, and the L-8 would lay in wait for a U-boat to appear. They were unsuccessful in their efforts as the U-boats had become wary of decoy ships and would not approach.
L-9 while running builder's trials on the measured mile off Provincetown, MA. in Cape Cod Bay, spring of 1916. Note that while essentially complete at this point she still has a temporary canvas bridge structure. This would later be replaced with a permanent steel bridge fairwater.
The USS L-10, with the American “A” added to her fairwater to avoid confusion with the British L-class submarines, in Bantry Bay, Ireland. There is no date on the photo but the assumption is circa 1918. The L-10 was one of the best American subs working out of Ireland.
LT Vincent Arthur Clarke, Jr. was sent for submarine training at New London, Connecticut. Upon graduation he was assigned to submarine duty and sent to the Azores. From there he was made the commanding officer of the L-10, probably relieving LT Newbold T. Lawrence Jr. as CO. The L-10 operated out of Bantry Bay, Ireland for the duration of the war.
This command garnered Clarke a Navy Cross for his persistence in making the L-10 one of the "hot running boats" in WW I, racking up over 1700 hours out on patrol in pursuit of the enemy. War patrols in WW I were only an average of 10 days duration due to the sub's limits on food, water and fuel.
LT Clarke is probably the officer on the bridge in this photo as the L-10 backs away from her mooring. The crew look to be stowing the mooring lines in preparation for possibly heading out on a war patrol looking for German submarines.
L-11 running builder's trials in Cape Cod Bay off Provincetown, MA., summer of 1916. She still has a pipe frame and canvas bridge structure. Most likely the boat is running at her full speed of 14 knots, testing the upper range of engine power.
Here we have here two unidentified EB design L-class submarines. The unique shape of the bow planes pivot housings and the unique shaped “bullnose” on the tip of the bow are identifiers of the EB design for this class. The two flat rectangular covers, one on top of the other over the bow planes pivots can be seen. This cover was unique to the L-1, L-2, L-3 and L-4 and then again with the L-9, L-10, and the L-11. Submarines L-5 through L-8 were built to the Lake Co. design and did not have these pivot covers. This variant of the L-class of submarine were commissioned by late 1916. The L-6 thru L-8 variant were commissioned in 1917. L-5 was commissioned in 1918.
Both submarines have a tall forward radio mast. In looking in other archives we have seen only the L-1 with such a mast. So, possibly one of these two vessels could be the L-1 but it could just be coincidence that there only exists one image, other than this one, with these masts. Radio was new and trials were being made all the time.
Neither submarine have any sign of having SC tube listening gear installed at this point. So, a possible date is closer to commissioning, perhaps a late 1916 or early 1917. But for sure this is before the U.S. entered WW I on April 6, 1917. The submarines still are using the old-fashioned pre-war canvas bridge shelters that proved too flimsy to withstand the pressures of diving with it erected. They were too time consuming to try and take down in actual war time conditions.
The British, having been at war with Germany for two years, taught their American cousins a lot of practical things about actual submarine warfare including the development and use of the metal chariot bridge surround that could remain in place while diving and withstand those pressures. Soon almost all U.S. submarines had this revision installed.
Once these subs reached Europe, the British, to avoid confusing their L-class submarines with the American L-class, required the Americans to paint an "A" in front of their numbers. All combatants still wore hull identification at this time. In later conflicts all ID was painted out so an enemy could not keep track of sub movements, this is even done to this day.
These two submarines are moored to a monitor-type tender that is also not identified but could possibly be the USS Tonopah (BM-8). Three sailors are standing on the tender's deck. There also seem to be at least two people each on the submarine's decks.